We also tried impedance analyser application, both with and without LCR extension board, and in any case we could reach the limit of 50MHz.

I tried to add other frequencies in the front-end (in the LCR_FREQUENCY select/dropdown), which should basically just send the frequency to the backend as a parameter, but 500kHz is enough to make the app crash. I tried to find any error log, didn't find anything.

Is it possible to "push" the LCR meter app to 50MHz (or at least few MHz) ? How ?